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Discussion Starter #1
Greetings all,

Car - '92 AE100 Corolla with 5-AFE engine

A few weeks ago my radiator cooling fan stopped working. Long story short, the car overheated, blew the water pump and head gasket in the process. Fan and water pump have been replaced, the head was resurfaced and new OEM valve stem seals were installed since the old ones were toast.

Sidenote: The car would smoke a bit on start up and acceleration before the head gasket blew. I'd go through 1 quart of oil a month.

Driving home from the mechanic I noticed a slight squealing noise but figured it was just a belt tensioning issue which it was. When I got home, I noticed the belt was EXTREMELY loose I could move it by hand about 3 inches inward and outward. I tightened it immediately. Since then I have had exhaust smoke that has hints of white, light grey and blue upon heavy acceleration and burn half a quart of oil after 4 hours of driving! No visible smoke upon start-up.

I suspect piston rings are the culprit but would like some of you guys' opinions on the situation and how I can test and be sure what's causing this, whether rings or something else, without having to tear the engine down just yet.

Any help is greatly appreciated.
 

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First of all, is it the 4A-FE or 7A-FE? (I'm assuming that this is a typo unless you have a non USDM model with the 5A-FE engine) I know that the 7A-FE is infamous for burning oil due to bad piston rings.

You said that that the car is blowing white smoke. That's an indicator of burning coolant. Pop the radiator cap (while engine is cold) and see if the coolant looks funny. It should be a consistent green color unless special Asian formula was added. Start the engine and see if the coolant is bubbling.

Also do a compression test on the engine. It would have at least 190 PSI per cylinder with maximum of 14 PSI difference between the lowest and highest.
 

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Discussion Starter #5
I haven't lost any coolant since getting back the car from the machine shop. I let the car warm up to operating temp and did not notice any bubbles in the overflow tank either. Coolant color is also good and looks normal to me.

I'll definitely get that compression test done when I have the time to buy the kit and do it myself because its actually cheaper for me to buy the kit than pay a shop to do the test for me (sounds backward I know). Thanks for those PSI specs patx35!

And yes it's the JDM model.

Thanks again all.
 

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Discussion Starter #6
Update:

I've started noticing a drop in coolant these past two weeks or so. The car is still burning oil as well. There are no visible leaks of either coolant or oil at all.

I did a compression test with the temp in the middle between C and operating temperature. Dry and wet (added half a cap of 10w-30 engine oil to each cylinder)

Compression test results:

Cylinder 1: Dry - 200 psi - Wet - 250 psi
Cylinder 2: Dry - 220 psi - Wet - 260 psi
Cylinder 3: Dry - 205 psi - Wet - 260 psi
Cylinder 4: Dry - 220 psi - Wet - 250 psi

Any thoughts guys ?
 

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You defiantly have a compression issue. I would run some engine flush through it to see if you can melt any sludge that may be gunking up the rings.
 

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So the valve stems, head gasket, and a few other gaskets replaced yet it is losing oil and coolant with no visible leaks?

Engine is likely screwed.



If an engine seriously overheats even once, that is all it needs to mess up the head and/or block and God knows what else. it is like leaving something on the stove too long - once it is burned, it is burned.

If you want to try to fix it or have it fixed, it is going to need serious work (and money).



You can try less extreme repairs but when an engine has an internal leak or the piston rings are shot, that means internal damage.
 

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Sure those compression numbers are PSI and not some other unit like Kgf/cm^2?

Could be they shaved way, way too much off head to flatten it.

Might also be improper headgasket with incorrect thickness.
 

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Discussion Starter #14
Yea I'm positive it's PSI. I'll re-do the test this coming weekend to see if I get the same results. If anything changes I'll update.

Hmm, I didn't think of the head resurfacing potentially causing this.. interesting. Thanks for that.

When I get the chance I'll do an engine flush like Frige suggested and hope it at least reduces the burning.

Thanks guys
 

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I'd guess the compression gauge is off if anything, especially if it's a cheap one.
 

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Discussion Starter #16
I think it's a decent quality gauge I used. The brand is Draper.

It's this, [ame]https://www.amazon.co.uk/Draper-37442-Compression-Tester-14X18mm/dp/B0001K9TV0[/ame].

Or maybe the previous owner put in high compression pistons even. I haven't a clue.
 

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Sure those compression numbers are PSI and not some other unit like Kgf/cm^2?
Considering the conversion factor between PSI and any of the other common pressure units (KPa, bar, atm etc), I'd be much more likely to believe slightly high but believable PSI numbers compared to astronomically high or low KPa/bar etc.
 

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Discussion Starter #18 (Edited)
Update:

I pulled the spark plugs and did a piston soak using Marvel Mystery Oil. I put two ounces in each cylinder, and rotated the engine by hand periodically. After 24 hours, all of the oil had drained past the rings and into the crankcase. I added another two ounces to each cylinder and let that sit another 24 hours. The following morning I installed plugs and started her up and let the engine idle for 15 minutes, revving it periodically. I then installed new spark plugs, changed the oil and filter (3 liters of Shell Helix), plus 4 ounces of MMO to the crankcase, and 4 ounces to the gas tank.

That was a month ago, and I have noticed that oil consumption has been cut in half. I still get some smoke under hard acceleration, but not nearly as much as before.

I also re-did the compression test and realized the numbers have dropped more or less even for the dry test.

Compression Results in PSI:

Dry test - 200, 205, 205, 205
Wet test - 215, 240, 240, 230

There is some carbon visible on the top of the pistons, and the head has been resurfaced so I suspect those two factors contribute to the high compression numbers. Also, there's still a relatively large increase in psi in cylinders 2, 3, and 4 when the half cap of oil was added and the wet test performed, compared to the dry test results. I plan to do another soak prior to my next oil change and see if the numbers will drop a bit more.

I hope this is helpful to someone.
 

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How many miles are on the engine?

Are you still losing coolant?

Is your coolant or oil discolored?

You might want to pressure test your cooling system at the radiator cap.
 

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Discussion Starter #20
The engine head and block are original and have 295,000 miles.

The coolant level has dropped a bit. What I’ve noticed is that if I fill the coolant to the “cold fill” line, when the engine gets up to temp, the coolant expands a lot and comes out the drain hose on the reservoir cap. No bubbles visible. When it cools down, there’s only about an inch left in the reservoir. From there on, the level very slowly drops before I have to top up.

Could the engine be running a couple degrees too hot because of the higher than normal compression and causing coolant to evaporate ?

I’ll definitely get the system pressure tested because something is amiss here. Thanks
 
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